Sunday, December 6, 2009

So, this has been bothering me for a couple of months. I figure it may well be a figment of the data, or I am abusing the data. But I don't know, so I'll put it up... comments welcome.

This is a graph of Implied Average Online Display Ad CPM, 2006 through Q2 2009 (left axis, thick blue line.) Implied Average CPM is ad spend divided by impressions.

The right axis and thin black line are impressions in millions, as per Thursday's post. This seems to show that as display ad impressions fell in 2008, ad spend did not fall as fast. For this to happen, CPM must have increased. This is both not what has happened, anecdotally, and is hard to believe in this era of expanded access to non-premium inventory. But I hate to think I believe the data when it confirms my preconceptions and then disbelieve it when it doesn't.

As someone who used to work for two different prognosticators, Jupiter Research (then Jupiter Media Metrix, now Forrester) and Nielsen/NetRatings, I can confidently say these numbers are complete bullshit.

Hmmm, I just went and checked comScore data for June 2009. It said 500b US impressions in June. Not all of those had ads, but some probably had more than one. That projects out to one overwhelming conclusion: Good data is hard to come by.